The invention relates to a personal document, such as a personal identification, passport, driver's license, or employee identification, and relates to a method for producing said personal document.
A number of applications are known from the prior art in which integrated circuits are incorporated in documents, for instance in the form of IC cards. These facilitate rapid, sometimes automated verification and make it more difficult to falsify such documents. Furthermore, additional data such as e.g. biometric data for authenticating the document's possessor can be stored in this manner.
However, the disadvantage of incorporating ICs in documents is that in many cases they must be very flexible and they are subjected to different and very heavy loads, in particular bending loads, during their period of validity. ICs based on silicon, however, are brittle and break easily, so that it is not always possible to assure the desired durability. Because of this, chips are normally embedded in the casting compound and incorporated in IC cards in this manner as “chip modules”, but instead of being an integral component in the cards, they are foreign bodies whose mechanical properties are clearly different from the substrate material of the cards. In addition, the contacts between IC and conductor are particularly endangered when, while the document is being bent, the substrate bends but the IC remains rigid. This imposes very stringent limits in particular on the size of ICs in flexible documents.
In the past it has been possible to incorporate large and more powerful, thick ICs in non-flexible documents, for instance the passport covers, because the rigid cover protects the document and IC. In the case of chip cards, which are likewise relatively rigid, a thickness of at least 760 μm is necessary, but little space is left over for designing the card structure, due to the size of the chip module and its thickness of, for instance 35 μm. Finally, incorporating a chip renders the structure of the document less stable overall, making it vulnerable to manipulation by potential counterfeiters.
Known from the prior art (DE 196 51 566 B4) is abrading silicon ICs on their back side, thus making them thinner. Such ICs, which in extreme cases can be thinned down to 10 μm to 15 μm, are much more flexible than conventional thick chips so that they can even be incorporated, for instance, into thin documents that have paper as a base (DE 196 30 648 A1).
However, when incorporated into personal documents, even this type of IC still represents a foreign body in the document. These ICs bond only incompletely to the substrates that are normally used for personal documents, such as paper and plastics, in particular polycarbonate and polyethylene terephthalate. Because of this, it is possible to intentionally or even inadvertently separate the document from the IC; so that there is still a risk of technical failure and opportunities for manipulation. The object of the invention is to create a personal document that is improved in this regard.